Polymer modified asphalt compositions and related methods

Abstract

Polymer modified asphalt compositions for roofing applications and related systems and methods are provided. A polymer modified asphalt composition comprises at least 80% by weight of an asphalt based on a total weight of the polymer modified asphalt composition, a polyolefin having a number average molecular weight of at least 25 kDa, and an ethylene vinyl acetate copolymer.

What is claimed is: 
     
       1. A roofing shingle comprising:
 a substrate; and 
 a coating on the substrate, 
 wherein the coating comprises:
 10% to 90% by weight of a polymer-modified asphalt composition based on a total weight of the coating,
 wherein the polymer-modified asphalt composition comprises:
 at least 84% by weight of an asphalt based on a total weight of the polymer-modified asphalt composition; 
 1% to 15% by weight of a polyolefin based on the total weight of the polymer-modified asphalt composition; and 
 1% to 15% by weight of an ethylene vinyl acetate copolymer based on the total weight of the polymer-modified asphalt composition, 
  wherein the ethylene vinyl acetate copolymer has a melt flow index of at least 30 g/10 min as measured according to ISO 1133; and 
 
 
 10% to 90% by weight of at least one filler based on the total weight of the coating; and 
 
 a plurality of granules on the coating. 
 
     
     
       2. The roofing shingle of  claim 1 , wherein the substrate comprises at least one of a fiberglass mat, a polyester mat, or any combination thereof. 
     
     
       3. The roofing shingle of  claim 1 , wherein the polyolefin comprises at least one of a polyethylene, a polypropylene, or any combination thereof. 
     
     
       4. The roofing shingle of  claim 1 , wherein the polyolefin has a number average molecular weight of at least 25 kDa. 
     
     
       5. The roofing shingle of  claim 1 , wherein the polyolefin has a polydispersity index of 10 or less. 
     
     
       6. The roofing shingle of  claim 1 , wherein the ethylene vinyl acetate copolymer has a melt flow index of 30 g/10 min to 150 g/10 min as measured according to ISO 1133. 
     
     
       7. The roofing shingle of  claim 1 , wherein the ethylene vinyl acetate copolymer comprises 10% to 40% by weight of vinyl acetate based on a total weight of the ethylene vinyl acetate copolymer. 
     
     
       8. The roofing shingle of  claim 1 , wherein the polymer-modified asphalt composition comprises 84% to 95% by weight of the asphalt based on a total weight of the polymer-modified asphalt composition. 
     
     
       9. The roofing shingle of  claim 1 , wherein the polymer-modified asphalt composition comprises 1% to 10% by weight of the polyolefin based on a total weight of the polymer-modified asphalt composition. 
     
     
       10. The roofing shingle of  claim 1 , wherein the polymer-modified asphalt composition comprises 1% to 10% by weight of the ethylene vinyl acetate copolymer based on a total weight of the polymer-modified asphalt composition. 
     
     
       11. The roofing shingle of  claim 1 , wherein the polymer-modified asphalt composition does not comprise a styrene-containing polymer. 
     
     
       12. The roofing shingle of  claim 1 , wherein the at least one filler comprises limestone. 
     
     
       13. The roofing shingle of  claim 1 , wherein the polymer-modified asphalt composition has a softening point of 190° F. to 320° F., as measured according to ASTM D3462. 
     
     
       14. The roofing shingle of  claim 1 , wherein the polymer-modified asphalt composition has a penetration point of 15 dmm or greater at 77° F. 
     
     
       15. The roofing shingle of  claim 1 , wherein the polymer-modified asphalt composition has a viscosity of 150 cP to 1000 cP as measured according to ASTM D4402 at 400° F. 
     
     
       16. A roofing system comprising:
 a roof substrate; 
 a first roofing shingle; and 
 a second roofing shingle;
 wherein the first roofing shingle and the second roofing shingle are secured to the roof substrate; 
 wherein a portion of the first roofing shingle overlaps a portion of the second roofing shingle; 
 wherein each of the first roofing shingle and the second roofing shingle comprises:
 a substrate; and 
 a coating on the substrate,
 wherein the coating comprises: 
  10% to 90% by weight of a polymer-modified asphalt composition based on a total weight of the coating, 
  wherein the polymer-modified asphalt composition comprises: 
  at least 84% by weight of an asphalt based on a total weight of the polymer-modified asphalt composition; 
  1% to 15% by weight of a polyolefin based on the total weight of the polymer-modified asphalt composition; 
  1% to 15% by weight of an ethylene vinyl acetate copolymer based on the total weight of the polymer-modified asphalt composition, 
  wherein the ethylene vinyl acetate copolymer has a melt flow index of at least 30 g/10 min as measured according to ISO 1133; 
  10% to 90% by weight of at least one filler based on the total weight of the coating; and 
 
 a plurality of granules on the coating. 
 
 
 
     
     
       17. The roofing system of  claim 16 , wherein the polyolefin has a polydispersity index of 10 or less. 
     
     
       18. The roofing system of  claim 16 , wherein the ethylene vinyl acetate copolymer has a melt flow index of 30 g/10 min to 150 g/10 min as measured according to ISO 1133. 
     
     
       19. The roofing system of  claim 16 , wherein the ethylene vinyl acetate copolymer comprises 10% to 40% by weight of vinyl acetate based on a total weight of the ethylene vinyl acetate copolymer. 
     
     
       20. The roofing system of  claim 16 , wherein the polymer-modified asphalt composition comprises 84% to 95% by weight of the asphalt based on a total weight of the polymer-modified asphalt composition.